Radio frequency identification (RFID) technology uses electromagnetic energy as a medium through which to send information. Typically, RFID tags are devices which are affixed to various articles so that these articles may be easily tracked during movement from one point to another or identified during a sale transaction. Therefore, one may tag things such as assets, animals, and people so that they be identified or tracked automatically via a reader which is frequently connected to a host computer that may contain additional data tied to an object's identification number associated with the RFID tag. Furthermore, the RFID tag generally contains programmed information about an object to which it is attached. Through the use of such information, RFID technology may be used to identify objects automatically and without manual scanning operations as is required in most bar code systems.
An RFID tag typically includes a receiver and some type of transmitter, an antenna, and memory. Through the use of these components, RFID tags are enabled to receive, store, and transmit article-identifying data with a remote base station. RFID tags have been implemented using a variety of methodologies to allow a user to perform any number of desired identification finctions. For example, RFID tags may be read-only or read-write. Additionally, passive RFID tags may be implemented without batteries and draw their power from the radio frequency (RF) energy transmitted from the reader. As well, RFID tags may be low or high frequency depending on a user's desires.
While the variety of RFID tags described above work well for most situations, it is difficult to determine which RFID tag is being accessed by the base station when a large number of RFID tags are consolidated in a small area. Therefore, a need exists for an identification method which quickly and efficiently identifies individual items in a large group which is within a range of the base station.